How Do Ecological and Recreational Features of Waterfront Space Affect Its Vitality? Developing Coupling Coordination and Enhancing Waterfront Vitality

People are increasingly concerned with natural environment quality (NEQ) as well as recreation services (RS) as the popularity of natural experiences grows. Specifically, public spaces in ecologically sensitive areas must achieve coordinated eco-recreational development. Waterfront spaces fall into this category, providing a high-quality natural environment and facilitating various recreational activities. This paper uses two waterfront spaces, Foshan New City Riverfront Park and Nanhai Qiandeng Lake Park, as sample sites, divides 22 waterfront space samples into specific research objects, introduces dual variables for RS function and NEQ, and uses mathematical and statistical methods, such as Pearson correlation analysis, coupling coordination degree calculation, and redundancy analysis, to investigate the influence of different waterfront spaces on RS function and NEQ. Finally, we propose an optimization strategy for coupling and coordinating the development of the RS function and the NEQ of waterfront space. This paper found the following: (1) RS (number of public facilities) and natural environment quality (shoreline curvature) are the dominant factors in the vitality of waterfront space; (2) optimization of RS function will restrict the development of NEQ to a certain extent; and (3) the coupling and coordination of NEQ and RS function are positively related to the vitality of waterfront space. This study can be valuable for government officials and waterfront space planners as they develop social–ecological synergy models.